This invention relates to an apparatus for forming a cylindrical member, for example, a carcass band or the like constituting a pneumatic tire by firmly butt joining both ends of a belt-shaped member.
Cylindrical member forming apparatuses have been known, for example, as disclosed in Japanese Patent Application Laid-open No. 63-1,531. An apparatus disclosed in the Laid-open Application includes a forming drum having a continuous cylindrical outer circumferential surface on which a belt-shaped member is wound with a slight clearance between both ends of the member, and a disc-like guide roll. A frustoconical joining roll are arranged on an outer side of the forming drum. The apparatus further includes cylinders causing these guide and joining rolls to approach the forming drum to press the guide roll against an outer surface of the one end of the belt-shaped member and the joining roll against an outer surface of the other end of the belt-shaped member. The apparatus further includes moving means for pulling both the ends of the belt-shaped member closer together and butt joining the ends by rolling the guide and joining rolls along the clearance between both the ends of the belt-shaped member.
With such a disclosed apparatus, however, only the outer surfaces of the ends of the belt-shaped member are pulled closer together and butt joined by means of the guide and joining rolls. Therefore, there is a problem in that inner surfaces of the ends of the belt-shaped member in close contact with the forming drum are joined insufficiently with a low joining strength.